Arc-electrode and process for making it.



itlo Erawing.

mainly of two or more met 11271 which the ingredients are 11.-

JQEEPH L, R. HAYDEN,

SIGNDB TO GENERAL ARC-ELECTRQDE AND PROCESS FOR MAIQING IT.

rece es,

States, residing new and useful Improvements in Arc-Elem trodes and the Process of Melong Them, oi

which the following is e specification.

invention relates to are light eleccompounding the oxide irmly mixed. Electrodes oi this chsrecter are "preferably but not exclusively used cathrodes and. the process of odes in conjunction with anodes of carbon, "or of copper,

or'otlier metal. The different metallic oxide, oil which. such electrodes are composed have ordinarily different degrees oi iusibility, and vowing to the incomplete mixture of the wilds obtained by the ordi nary manner of melting-these electrodes, the

difierent oxids iuse separately, that is to sey, in succession, one oiter the other. in the pool whichiorms at the Working end of the cathode, so that these compounds which fuse more readily ere already in s .Q. uid stete when the more refractory ones-are still solid. It follows from this that the more refractory compounds do not iurnish to the are the amount of Vapor or gas which is due touhe proportion of these compounds in the sun position of the electrode, Thus, for instance, ingm electrode compounded of magnetite, rui'ile, chromite, or the oxid. oi chro miuin, end possibly some other slight udmizrture, like fiuorid of potessium, it hepens that when the magnetite in e perfeet-1y fluid state at the working end of the cathode, the rutile is only imperfectly molten and the chromite rosy still be in a solid state. As at result of this the evolutitui of vapor from the rutile is retarded, by reason oi: the fact that it is beh'ind the megncti e in iusibility. lnthis manner the are is deprived oi the luminosity which should. be imparted to it ,'by the titanium vapors. The efiectoi the dissirnulteneous i'usion oi the component parts of the compound is not observable at the beginning of the tion, butsfter the cathode has been used for some time it manifests itself in the change oft-color end dimming of the ere. it may well he that the are is maintained from the etite end rutile until these materials m 1 here been consumed at the point W ere the Specification of Letters Patent.

l l l l 1 L Patented inn. ii ie'iiu Anpiication filed August 17, 1808. Serial No. 445,797.

are issued from the working end of the electrode, and the are must then feed upon the chromite particles until these are consumed. During this stage the arc assumes the dull bluish tinge of the chromium are. Its luminosity is diminished to some extent, and the ore becomes hotter. The higher temperature is deleterious to the positive electrode. 1 have found that this periodic change of color and dimming oi? the luminous are, due to the ditl'erent degrees of fusibility oi its constituents, is mainly due to the incompleteness of the mixture obtained by the ordinary method of compounding such electrodes; and I found that it the ingredients employed in the composition of the electrodes are very intimately mixed, the differ ent constituents of the some, although noturally of diii'erent degrees of fusibility, will practically fuse together as a unit, so that. every constituent Will give its proportional amount of vapors to the era; and I here found that the requisite intimate mixture of these ingredients can be obtained in the following mannerz-lnsteed of mixing the constituents of the electrode by grinding each separately and then mixing them mechanically, or by grinding them all together, "which is'the,ordinery we of making an electrode of the, character above described, and by which process the mixture is necessarily incomplete, I melt the ingredients to gethcr in a crucible, so that a practically homogeneous body is obtained which, upon cooling, becomes very brittle, and is then easily powdered to any degree of fineness. The mixture oi the ingredients thus obtained is exceedingly uniform, and when filled in iron tubes or otherwise formed into pencils, and when these pencils ere used as cathodes in electric arc lamps, the pool formed at the Working end is composed of a iiuid mixture of all the constituents of the electrode, since now all oi them fuse at. sub-- stentielly the some time end the evolution of vapors or geses from the same proceeds uninterruptedly, each constituent giving vepors in proportion to its proportional quark tit l present in the moisture. llo "periodic dimming and changing oi color of light is observable in en electrode made in this manner," l

In the ordinary electrode composed ot' magnetite, tireuium chromite or chm nuuni mild; end from Mill I orid, the

' trode allowed to cool. This interferes with the subsequent starting of, an are. With my more uniformly,

I owdered, since it that with the abeve named ingredients, but with about ten per cent. more of titanium' obtained at about the melting point of cast.

process of compounding-these ingredients, I'am enabled to use a much higher percentage of titanium oxid than was heretofore used, as the intimate mixture of the ingredients results in a mass which is conducting even with a high percentage of titanium dioxid, and as the ingredients are consumed I the layer of slag is not present. The addedfamount of titanium dioxid in the electrode is an advantage, since the titanium vapors impart to the are a high degree of luminosity. I have found dioxid or rutile than has hitherto been practicable, a fluid mixture of the ingredients is The substances fuse together to a stony mass, which-can be very easily is very brittle. It is then lled into the iron tube in the usual maniron. black ner, -Wh16lf an increased eificiency.

What I clai'm'as new and desire to secure I by Letters Patent of the United States, 1s 1. An arc 1i ht electrode, the are supporting body of w ich consists of thepowder of and thereby an electrode is obtained givesincre ased steadinessoflight and.

afsolidified fusion containing metallic compounds.

2.- An are light electrode, the arc support ing body of which consists of the'powder-of a solidified fusion containing metallic oxids.

3. An are light electrode, the arc support-'- ing bod of which consists a solidi ed fusion'of mite and fluorid. of potassium.-

4. An are light electrode consisting of an iron tube packedwith of the powder of 5; An arc lamp elett/rqde consisting of an iron tube packed with the 'powder of a solidified fused mass containing metallic'oxids and a fluorid.

In witness whereof, I have hereunto set" my hand this 8th day ofAugust, 1908,

Witnesses:

BENJAMIN B. HULL, HELEN Onronn.

magnetite, rutile, chro;

the powder of. a solidified fusedmmass containing metallic 

